An extrusion die for manufacturing laminates having two or more juxtaposed layers of extrudates includes a feedblock having therein a corresponding number of separate flow paths for each extrudate in the laminate. The thickness of each juxtaposed layer of the extrudate is generally a function of the flow rate of the extrudate and the size (e.g., the height) of the opening of the corresponding flow path through which the extrudate exits. Accordingly, for manufacturing laminates wherein the thicknesses of the one or more layers of the extrudates are different, it becomes necessary to dis-assemble the feedblock in order to remove and exchange dies of different sizes in order to change the size of the corresponding opening through which the extrudate exits. As will be apparent to one skilled in the art, the actual (or exact) thickness of each juxtaposed layer of the extrudate cannot be pre-determined with any degree of certainty until after the die has been re-assembled and operated. If the thickness of the one or more layer is not as expected and/or is unacceptable, then the entire process of dis-assembly, adjustment and re-assembly must be repeated. As can be appreciated, this is an expensive and time consuming proposition and prone to error. Even after the thickness of the one or more layer of extrudate has been set as desired, a change in the flow rate of an extrudate can affect the thickness of the layer of that extrudate in the laminate. For example, if the flow rate decreases, then the amount of extrudate exiting the flow path will also decrease resulting in a thinner layer of that extrudate. This may also affect the overall thickness of the laminate and/or the thickness of the layers of the other extrudates in the laminate.
Accordingly, there exists a need for an adjustable feedblock wherein the thicknesses of the layers of the one or more extrudates of a laminate can be manipulated without the necessity of dis-assembling, adjusting and re-assembling the die.